The present invention generally relates to bulk bag lifting frames. More particularly, the invention relates to retainers used in conjunction with bag lifting frames which permit easier loading and unloading of bags from the lifting frame.
Large bag like containers are often used for the shipment of bulk materials from one location to another. These bulk bags have a capacity ranging from approximately twenty cubic feet up to seventy cubic feet. The bulk bags are generally constructed with bag loops on the top of the bag which are connected to a lifting frame for holding the bags while they are being filled or emptied and occasionally for transporting the bags from one location to another. The bag loops are generally constructed of a strong web-like material which is sewn onto the upper corners of the bag.
The bag lifting frames generally comprise a system of horizontal frame members adapted to be supported by a hoist (See FIG. 2) or a fork lift (See FIG. 7), or other support means. Most prior art bag lifting frames include hooks or clips for holding the bag loops. A representative prior art hook 20 is shown in FIG. 1. The hook 20 is mounted on the horizontal frame member 12 and includes a J-bend portion 22 which receives and supports the loop 42 and a clasp member 24 which closes the hook 20 to prevent inadvertent release of the bag loop 42. The clasp member 24 is generally biased to the closed position. During loading of a bag, the biased clasp member 24 gives to permit the loop 42 to be looped over the J-bend 22. While it may be possible to load a loop with one hand, the process often requires a second hand to prevent rotation of the clasp member 24 during loading. Additionally, the loop 42 must be aligned close to the center of the J-bend 22, otherwise the frame may be subject to undesirable side loads. To remove the loop 42, the clasp member 24 must be forced toward and maintained in an open position to permit the loop 42 to be removed. Such a process generally requires two hand operation, one hand to open the clasp member 24 and a second to lift the loop 42 out of the hook 20. While it may be possible to release a loop with one hand, such a process requires great dexterity and subjects the operator to possible pinching by the clasp or other dangers.
As such, there is a need for a loop retainer which allows easier loading and unloading of a bag loop.
The present invention relates to bag loop retainers used in conjunction with bulk bag lifting frames. The retainers include opposed first and second retainer plates which are secured to the lifting frame. The plates are aligned relative to one anther such that a projecting portion of one of the plates nests within an receiving portion of the other plate. The plates thereby define a non-linear passage into a retainment area which receives and retains the bag loop. In the preferred embodiment, the plates are configured such that the passage has a zig-zag configuration. passage has a zig-zag configuration.